The Outer Space Treaty, formally the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, is a multilateral treaty that forms the basis of international space law. Negotiated and drafted under the auspices of the United Nations, it was opened for signature in the United States, the United Kingdom, and the Soviet Union on 27 January 1967, entering into force on 10 October 1967.
States Parties to the Treaty undertake not to place in orbit around the earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction, install such weapons on celestial bodies, or station such weapons in outer space in any other manner.
The moon and other celestial bodies shall be used by all States Parties to the Treaty exclusively for peaceful purposes. The establishment of military bases, installations and fortifications, the testing of any type of weapons and the conduct of military manœuvres on celestial bodies shall be forbidden. The use of military personnel for scientific research or for any other peaceful purposes shall not be prohibited. The use of any equipment or facility necessary for peaceful exploration of the moon and other celestial bodies shall also not be prohibited.
Not as things stand from a treaty standpoint.
https://en.wikipedia.org/wiki/Outer_Space_Treaty
https://en.wikisource.org/wiki/Outer_Space_Treaty_of_1967
That is so 2023.
https://www.foreignaffairs.com/russian-federation/why-russia-might-put-nuclear-weapon-space
Well, Russia hasn’t actually violated it yet. We just have intelligence that it was being considered.
If the treaty breaks down, then, yeah, maybe we could see war on the Moon in the future.